Fluid pressure brake



OV. m1@ @N NW o @T M lNvER y GLY DE QFARMER BY ATTORNEY c. FARMER FLUID PRE May 23, 1939.

S'SURE BRAKE Filed June 2, 1937 *flatented May 23, 1939 u FLUID PRESSURE `BRAKE Clyde C.`Farmer, Pittsburgh,` Pa., assgnor to The Westinghouse lAir Brake Company; Wilmerding, Pa., acorporatiori of Pennsylvania @This inventionrelates to a vehicle iiuid pressure brake equipment,` and more particularly to l, Eimproved means forcontrolling `the supply of iluidlunder pressure from an application device r"to la" brake `cylinder through a pipevvhere there iismore than usual danger of `breakage or rupture l lof the pipe, or of the development of `a leak of,`

` serious proportions. l l l ff'lhe brake i equipment for certain types of n l0 vehicles, such as for-alocomotive and tender, in-

l' cliides` a-plurality of brake cylinderswhich are supplied with `fluid-minier pressure from a com rnon` source, which may be the main reservoir son theflocomotive.

Zdtender through ilexible hose and couplings.v

` @The brake cylinder `c )rrthe tender'is `of rela- `tively large size, and order "toysecurefa rapid `application `ofgthe brakes `."intlie tender, it is `necessary tofemploy a pipeof largeliiovvy capacity i lctolsupply fluid under pressure` to the tender brake 'A cylinder.

"cylinder is broken, or `the"`hosefand` coui plingsbeccme disconnected, or 'if asaresult of a 30" similar condition, fluid is Areleased fremdes `pipe "l during an application of the brakes,`l`u"id may "be released from thesource so rapidly that the pressure therein cannot be maintained `by the 'air ocompressors assocated therewith. 'Inadditiomas y alresult of therapid release of uidfrom the vbranchof the supply pipe leading to the tender brake eylinder, the pressure `or the fluid in the other brake cylinders supplied .from the supply cpipe will be reduced, and there will be a partial y for complete `failure of the brakes-on the locomotive,

control device adapted to lbe interposed Ain` the torestricttherate of flow of fluid lv-througlfi.the

f V pipe ,-afterhatimeinterval if the pressure of the f fluid in the brake cylinder doesfnot 4build up in thenormal manner.`

A further .object `of the invention is to provide ajcontrol :device of the type described which-in fj corporates means to permit thesupply fof uid runder pressure lto the brake cylinder at a re- `I Lstricted rate at all times, to thereby prevent la failurepf the-supply `of "fluid to thebrakefcylinder Some of `these brakecylinders` i *are mounted on the locomotive, and'` some of l l them rare mounted on the tender. Fluidunder c "pressure is supplied -tof these brake cylinders l through a common suppl-y' pipe, aybranch of which is connected tothe brake cylinder onthe' VIi for `any reason the pipelcading the tender MIt is anobject Aofthis invention toprovide a ,in pipe `leading toa brakencylinder, and, operativeV as a result of improper voperationof the .control device. ,i l

Another object of the invention is to. provide an improved control device of 'the type described, and which corporates means to permit a rapid ilow of f luid from the brake cylinder to thereby permit a Vrapid release of the brakes. u

A further object of the invention is to provide ,a

` control device of the 'type described which is responsive .to `the pressure of the uid ina timing reservoir to which fluid is supplied at a restricted rate .o-n .thesupply .of uid -to the brake cylinder, andincorporating `means operative on the release ofiluid from thecbrake cylinder to release fluid l from the timing reservoir ata rapid rate. v

. Another object l of ,the :invention:is-toilrovde al. control device of the type described :which is 1y simple andrugged inconstruction, and `which isipositiveein operation.

A further` ebjeet of the levenden is prende 2 animproved control ,de-vice o f the :type descrbdv.Other `objects of `the invention 4and features of novelty will be `apparent from :the following description taken in connection with v,the accompanyingdrawing., `the single fgure of wfhihls ea "diagrammatic view, largely in section, ,of a ebrale equipment A,incorporatirlg a control `deyice ernbodying my invention. I

, Referring ,to `the drawing, ,there is shown `therein a vehicle brake `equipment which may employedxon a locomotive Land. tender, although it may be employed on a vehiclepf `another ftype,` such as `a vehicle having truck mounted brake cylinders which are supplied with `'fluid 'eunderv pressurethrough pipes having sections of flexible hose interposed therein. `As shown, ithe `brake equipment comprises ,a reservoir il, which maybe the .main reservoir on a locomotive, and which is ,charged with `fluid 'under :pressure :in `the usual manner by asuitable air compressor, het :,shoyvn. o

A ,brake` application valve device indicated generally bythe reference :numeral 2 ;isprov ideud, and `maybe `of anysuitable well known construction. The .application valve device `2 controls lthe supply :of `fluid from the-reservoir l to a ksupply 45 pipe 4- leading .to brake cylinders 5 4,and f6, which may be mounted on the locomotive, 4and `to a, brake `cylinder s1, `which may be mountedfon ,the tender for the locomotive. 4The.,tllplical'fion valve device ,2 also .controls the release of luid under 50 pressureffrom the supply rpipe 4.v e

The control device provided :by thisiinventiongis indicated generally by the reference 4numeral 8,1

and :is interposed in the 'branch pipe r9 :leading from; the supply pillen: to the :tender .brake cylin- 55.;V

g cylinder l.

der 'I at a point in this pipe between the supply pipe 4 and the flexible hose and couplings I3 by means of which connection is established between the locomotive and tender.

The control device 8 comprises a body having a passage i2 therein to one end of which is connected the end of the branch pipe 3 leading from the supply pipe 4, while the other end of the passage I2 has connected thereto the portion of the branch pipe 9 leading to thebrake cylinder 1. The passage I2 has interposed therein a choke or restriction i4, which is adapted to permit iluid under pressure to flow to the brake cylinder 'I at a relatively rapid rate, but sufficiently restricted to provide for a purpose to be hereinafter described, an eiective pressure differential between the pressure of the fluid in the passage I2 at the supply side of the choke I4, and the pressure of the uid in the brake cylinder side of the choke I4 when there is a flow of fluid under pressure through the passage. l

The control device 8 includes valve meansl5 for controlling the supply of fluid. under pressure through the passage l2 to the tender brake As shown the valve means I5 comprises a stem orr plunger i6 mounted in` a bore in the body of the control device 8, and having therein an annular groove Il, which in one position o the stem i6 registers with the ends of the passage I2 to permit communication through the passage I2.

The stem I8 has formed integral therewith an enlarged head I8 which engages one face of a diaphragm 20, which is subject on one side to the pressure of the uid in an operating chamber 2 I and issubject on the other side to the pressure ofthe fluid in a pressure chamber 22.

- The body of the control device 8 has a projection indicated at 24 formed thereon, and adapted to be engaged by a face of the diaphragm 20. A

coil spring 25 extends between the lower end'of the stem I6 and a threaded plug 25, and yieldingly urges the stem i8 upwardly, as viewed in the drawing, so that the diaphragm 2l] engages the projection 24. In this position of the stem I8, the groove Il therein is in registration with the passage I2 topermit the flow of fluid through this passage.

The operating chamber 2l is connected by way of a passage 28 with the passage I2v at a point therein on the side of the choke or restriction I4 adjacent brake cylinder. It will beseen also that the passage 28 communicates with the pas- Y sage I2 at a point therein on the side of the valve means I5 adjacent the brake cylinder l.

The pressure chamber 22 is constantly connected by way of a passagev30 with a timing or volume reservoir 3|, which is connected to a rela.- tivelyv large passage 32 which is open to the area within a seat rib 33. A check valve 34 is provided, and is mounted in a chamber 35 which is interposed in the passage I2. A coil spring 36 is mounted in the chamber35, and yieldingly presses the check valve 34 against the seat rib 33 to cut off the flow of fluid from the chamber 35 to the passage 32, and thus to the reservoir 3| and the pressure chamber 22.

I'he body of the control device 8 has a passage 31 formed therein leading to the passage 30 fromthe passage I2 at a point therein on the side of the choker I4 adjacent the supply pipe 4. This passage hasachoke or restriction 33 interposed therein, s

kThe control device. 8 incorporates a passage which by-passes the valve means 'I5 .and throughr which fluid under pressure may flow at a restricted rate from the supply pipe 4 to the brake smaller flow capacity than the choke I4.

The control device 8 provided by this invention incorporates means to permit a rapid release of uid under pressure from the brake cylinder l on the release of fluid from the supply pipe 4. As shown, a check valve 44 is provided and engages a seat surrounding the end of a passage 45 leading from the passage 40. The check valve 44 is mounted in a chamber 4S through which the passage I2 extends. The chamber 46 is located on the side of the choke I4 adjacent the supply pipe 4, whilea coil spring 48 is mounted in the chamber 46 `and yieldingly presses the check valve 44 to the seated position to prevent flow of fluid from the passage I2 to the passage 45 and thence to the brake cylinder 'I.

The control device 8 is shown in the drawing in the position which it assumes when the brakes are released, at which time the application valve device 2 connects the supply pipe 4 to the atmosphere. If it is desired to apply the brakes, the application valve device is operated to out off the connection between the supply pipe 4 and the atmosphere, and to supply fluid under pressure from the reservoir I to the supply pipe 4.

On the supply of fluid under pressure to the supply pipe 4, uid flo-ws to the locomotive brake cylinders 5 and 6, and also to the branch pipe 5 leading to the tender brake rcylinder l.

On the supply of iiuid under pressure to the branch pipe 3, iiuid iiows to the chamber 35, but as the check valve 34 is held in the seated position by the spring 36, fluid cannot flow to the passage 32 leading'to the timing reservoir 3l and to I' the pressure chamber 22.

Fluid under pressure supplied to the passage I2 also flows to the chamber 46, but as the check valve 44 is held in the seated position by the spring 48, fluid under pressure cannot flow from the chamber 45 to the passage 45, and thence by way of the passage to the brake cylinder l.

Fluid under pressure supplied to the passage i2 flows through the choke or restriction I4, and around the annular groove II in the stem I6 of the valve means I5 to the portion of the passage I2 to which is connected the portion of the branch pipe 9 leading to the tender brake cylinder 'I.

Fluid under pressure supplied to the portion of the passage I2 to which is connected the portion of the branch pipe 9 leading to the tender brake cylinder 'I, iiows by way of the passage 28 to the operating chamber 2I at the face of the diaphragm 22. Y l

On the supply of fluid under pressure to the brake cylinder 'I there will be an increase in the pressure of the fluid therein, assuming that the pipe connections leading to the brake cylinder remain intact, while there will be a corresponding increase in the pressure of the fluid in the operating chamber 2I at the face of the diaphragm 20.

` On the supply of uid under pressure from the supply pipe 4 through the A'branch Pipe!!` tothe "passage I2 in the control `device `8,-*f1uidunder pressure flows `at a restricted rate through the ,chke `to the passage" 3D to gradually increase s inthe operating chambenzl, and, `asa ``result`,"the t "spring will maintain 4the valve means |5in the position in which thegroove |`|-festa`blishes communication through I the `passage I 2;

a result,therefore, iiuid under pressure may flflcw from the supply pipe 4 to the` brake cylinder E'Ijfat arapid rate through the choke I4 to pro-` l duceg'a rapid increase in the pressure of the uid jinjthe tender brake cylinder 1, and a correspondingly rapid application of the brakes controlled "byllthis brake cylinder, Allihenfthe desired degree of brake application p, l "hasibeensecured, the application valve device 2 lismovedto theflap position, in the usual manner.

"Inl lap position, the `supply-"of fluidunder presi "sure to the supply pipe 4 is `cut oif, and thereafter `huid lunder pressure `ows from the passage I2 throughthe choke 38 to the passage 30, and

` f thenceto-the pressure `chamber 22 and thevollume or timing reservoir 3|, until the pressure of "the fluidin the pressure chamberl 22 and in the reservoir 3| hasj'equalized `with""the` pressure "of `the fluid in the brake cylinder 1.1

At"l this time,` "asthe pressure of thefluid in Q ftheljpressure chamber 22 and in the operating 4, `and thencetothe atmosphereto reduce the pressure of the fluid in thesebrake cylinders. In addition, iiuid under pressureflows from the i tender brake cylinder 'I by `Way of the branch I, lpipe LS9 to` thepassage `|2,1through the groove l. inthe stem`|6-`ofthefvalvemeans |5`to the other `portion of theipassage I2, through the chokeor restriction '|4, and thence throughthe chambers which is connected to the supplyl pipe V1|. VFluid f "released from the brake cylinder 1 ows to the supply pipe "4 Farid `is vented to the atmosphere throughthe application valve device 2.

fbrake cylinder I tothe passageland thence by xway of `the passage and pastthecheck'valve 44","which is `movedtothe'open position against `the1s1`31`ing 48, to the chamber 46 from 'which it ,l @flows by way of the passage I2 through the cham- Y l `i ber, and thence tofthe portion of the branch f jpipe elwhich is connected to the supply pipe'i4. llttwill be seen that fluid-under pressure released .5 i'r" the lbra-ke cylinder j'I y-past-"the *check `valve t pressure of the fluid inthe brake cylinder 'I4 and chamber 20| is substantially equal, the valvee "mfeanslj is maintained by the spring 25 inthe motive bralrecylinders 5 and 6 to thesupply pipe In addition, fluid under pressure flows from the` 44 'by-passes the choke 4, with the result that the rate of lrelease of fluid from the brake cylinder is not `limited ,by the 110W capacity of the choke I4, and accordingly the brakes may be released at a rapid rate.

On the release of fluid under pressure from the supplypipe `4, there is a reduction in the pressure of the fluid in the chamber 35', and the higher pressure of the huid in the timing reservoir 3|,

and inthe pressure chamber 22, operating on the' face .of the Vcheck valve 34 within the seat rib 33, moves the check valve 34 against the spring 36 to release fluid under pressure `from the timing reservoir 3| and 'the pressure chamber 22 tothe chamber 3-5, :from whichit flows by way of the branch pipe I9 te the supply pipe 4.

`The release of uid under pressure from vthe pressure chamber 22 and the timing reservoir 3| occurs at a relatively rapid rate because of the relatively largeflow capacity of the passage 32, and accordingly the pressure ofthe iuid in the pressure chamber 22 `is` reduced at least as `rapidly as the pressure in the operating chamber 2| at the opposite face of Vthe diaphragm'Z is` reduced, and, accordingly, the diaphragm 20is maintained in engagement with the projection 24 by the fluid in the operating chamberV 2|,

assisted by the spring 25, with the result that the the reservoir and consequentjfailure of the brakes. n V

"Assuming that `the branch pipe -"9 is ruptured or leaking at a point intermediate the control device `8 andfthe brake `cylinder I, then on the `supply of fluid under pressure to the supply pipe l 4` to effect an application of the brakes, fluid will `flow tothe branch pipe 9, and through the passage |2 and'choke I4 inthe control device 8. As it is assumed that the branch pipe `9 is ruptured at a point intermediate thebrake cylinder I and the control'. device f8, 'fluid under pressure supplied from 'the `control device 8 to the-branch pipe 9 will `not `reach, the brake cylinder `I, and

\ no back pressure will -be 'developed in the branch pipe 9 or in the portion of the `passage I2 on the side of the choke I4 remote from the supply pipe 4, or 'back pressure will not develop as rapidly as it does when the connections "to the brake cylinder remain intact. Accordingly, there will be` no increase in the pressure of the fluid the operating chamber 2|, or this` increase will not occur as rapidly as it normally does.

On the'supply of fluid under pressure frornrthe supply pipe '4 tothe branch pipe l9, there is an increase in the pressure of -the fluid in the portion of thebranchpipe 9 and of the passage l2 `on the side of the choke |4 adjacent the 4supply pipe 4, y'and fluid under pressure flows `through the choke'38 lto thepassage `3|) leading tothe pressure chamber 22 and to the `timing reservoir 3|.

' -a result ofthe supply; of iluid under pressure to the timing Vreservoir 3l and the pressure chamber 2`2g the pressure of the fluidthe'rein will increase ymore rapidly grthan f the pressure of =the fluid in the operating chamber 2l is increased at this time, and the force exerted by the fluid in the pressure chamber 22 upon the diaphragm Zil'vvill exceed the opposing force of the spring 25, and of the fluid under pressure present in the operating chamberl.v As a result, the diaphragm 2i] will operate to move the valve means I5 against the spring 25, thereby moving the annular groove Il out of registration With the portions of the passage I2 to thereby cut 0H the supply of fluid under pressure from the supply pipe 4 to the portion of the branch pipe 9 connected to the tender brake cylinder l. l

On operation of the valve means l5 to out off the iiow of fluid through the passage E2, fluid under pressure supplied from the supply pipe d through the choke Ill flows at a restricted rate through the choke 42 to the passage d, and thence to the portion of the passage I2 to which is connected the portion of the branch pipe 9 leading to the chamber lil. The flow capacity of the choke Il? is substantially less than the flow capacity of the choke it, and is proportioned to permit fluid under pressure to ow therethrough at a rate less rapid than the compressor associated With the reservoir I is capable of supplying fluid under pressure thereto, With the result that the air compressor is able to maintain the pressure of the iiuid in the reservoir I, even though fluid under pressure is constantly released therefrom through the choke 2.

The by-pass passage lit, including the choke L32, comprises means to supply fluid under pressure to the brake cylinder 'I at a restricted rate if the control device S is rendered inoperative at a time when the branch pipe 9 leading to the brake cylinder 'I remains intact. This prevents failure of the brakes controlled by thebrake cylinder 'Ir as the result of improper operation of the control device 3. A

On a subsequent release of the brakes by operation of the application valve device 2, fluid under pressure is released from the supply pipe d, While iiuid under pressure present in the timing reservoir 3i, and in the pressure chamber 22` iiows past the check valve 3d' to the chamber- 35, and thence to the supply pipe fi, as explained above., On this reduction in the pressure of fluid in the chamber 22, the valve means l5 is returned by the spring 25 to the position in which the annulargroove l'l establishes communication between the portions of the passage I2, and the control device 3 is conditioned to again permit the supply of fluid under pressure through the branch pipe 9 at a rapid rate.

In addition upon the release of fluid under pressure from the supply pipe i by the application device 2, any fluid under pressure present in the brake cylinder l may flow therefrom through the passages d@ and 45, and past the 'check valve M to the chamber $5, and thence to the supply pipe 4l. The passages lll and l5 provide means by which fluid under pressure may be released from the brake cylinder 'I in the event that the and to the pressure chamber 22, until the pressure of the fluid in these chambers is substantially equalized, as explained in detail above. If after the application ofthe brakes is effected, the portion of the branch pipe 9 leading from the control device 8 to the brake cylinder 'I is ruptured or broken, there will be a rapid reduction in the pressure of the fluid in the portion of the passage I2 on the side of the choke I4 adjacent the brake cylinder 1, and a corresponding reduction in the pressure of the fluid in the oper-ating chamber 2l. Because of the presence of the chokev I4, however, there will not be an equal reduction in the pressure of the iiuid in the passage I2 on the side of the choke I4 remote from the brake cylinder 1.

Accordingly, the fluid in th-e chamber 22 and in the timing lreservoir 3|, will be maintained at a somewhat higher pressure than the fluid in the operating chamber 2l, and the higher pressure ofthe iiuid in the pressure chamber 22 will cause the diaphragm 2B to move the valve means I5 against the spring 25 to cut off the flow of fluid through the passage I2, With the result that thereafter uid may flow from the supply pipe Il to the portion of the branch pipe 9 connecting the control device 8 and the brake cylinder 'I only through the choke 42. This restricts the rate of flow of uid from the supply pipe 4, and prevents depletion of the fluid under pressure in the brake cylinders 5 and 6, and in the reservoir i, and thereby prevents a failure of the brakes.

It will be seen that the control device provided by this invention is adapted to be interposed in the supply pipe leading from an application device to a brake cylinder, and that it operates in the event of a failure of the pressure of the iiuid in the brake cylinder to increase in the normal manner, to restrict the rate of ow of fluid from the supply pipe to the brake cylinder, and thereby prevent a depletion of the supply of fluid under pressure in the source, or in other brake cylinders which are supplied by the'supply pipe.

It Will be seen also that the control device provided by this invention incorporates a by-pass passage through which fluid under pressure may be supplied to the brake cylinder at a restricted rate to thereby permit the supply of fluid under pressure to the brake cylinder in the event that the control device fails to function in the intended manner.

Furthermore, it will be seen that the control device provided by this invention incorporates a by-pass passage extending around the valve means associated therewith, and through which fluid under pressure may be released from the brake cylinder at a rapid rate to thereby permit the release of fluid under pressure from the brake cylinder in the event that the valve means incorporated in the control device fails to function in the intended manner, and to also permit the release of fluid under pressure from the brake cylluder at an extremely rapid rate.

In addition, it will be seen that the control device provided by this invention includes valve means subject to the opposing pressures of the fluid in a timing or volume reservoir, and of the fluid in an operating chamber open to the pipe leading to th-e brake cylinder, and that on a reduction in the pressure of the fluid in the supply pipe, fiuid is released at a rapid rate from the volume or timing reservoir to quickly condition the control device for operation on the next application of the brakes.

VWhile one embodiment of the improved con- `1 trol, device providedby this inventionhas been fillustrated and described in detail, and while it has been described in connection with the brake c equipment for a locomotive and tender, it is to l 5 beunderstood that the inventionis not limited c to the details ofconstruction shown and described, nor is the control device limited toduse i, on a locomotive brake equipment, and` that numerous `changes and modifications may be made `10with`outA departing from thescope of the following `I"" `:`1a`irns.` c Y c ,i

Having now? described `my invention, what `I claim as new and `desire to secure by LettersPatnt,is:` v f* 1, "In a vehicle fiuidpressure brake equipment, n combination, a sourceA of fluid under pressure, a c `brake cylinder,l application means for supplying fluid under pressure from said -source to a comimunication throughlwhich fluid Vunder pressure `l `may be supplied 4to the brake cylinder through a 1 `restriction, a `volume chamber, means for sup,- plying iiuid under pressure to said volume cham- ,beru at a restricted rate from a point in said communication intermediate said restriction and the application means, `and valve means subject to the opposing pressures of the fluid in said volume chamber and of fluid supplied from said com- "munication throughan `always open passage at a "point therein intermediate therestrictionand fbrake cylinder for controlling theV flow of iiuid through `said communication. i ,c

`2In a vehicle fluid pressure brake equipment,

by-"pass passage ,extending around said valve jmeans and through which iluid may ow from therapplication means to the brake cylinder;`

, `in` combination, a source of fluid under pressure, a

"brake` cylinder, application means for supplying fluid under pressure from said" source to a com- `5(5munieation through which iluidunder pressure l "may be supplied to the brake cylinder through a restriction, a volumeV chamber, meansfor supplying iluid under pressure to said volume chamber at a-restricted rate from a point in saidcom- ,munication intermediate said restriction `and the applicationmeans, lvalve means constantly subject 9 "to the `opposing pressures of i the iiuid yin said :volume chamber and of the iiuid in said comi i "l tmunication at a point therein intermediate the `als rstriction and brake cylinder for` controlling the ffiloxvqof `fluid through said communication, `and a :c l,by-pass passage extending around said valve means and through which uid mayflow from "les `rapid` rate` than through said restriction, i

c In a vehicle fluid pressure brake equipment, n`cornbination, a plurality of `brake cylinders, application means for supplying-fluid lunder presureito a communication througnvvhich fluid c 5.' In a vehicle iiuid pressure c in combination, a source of fluid under pressure, j i a brake cylinder, application meansfor supplying through said communicatiomandan always open *3. i In a vehicle iiuid pressure brake equipment,

eapplicationmeans to the brake cylinder at a cylinders, 4andl avalve device `for controlling the l,supply of uid from said communication to one of` said brake cylinders,A said valve device comprising a bodyhaving a passage therein through which fluid is supplied from said communication i to said .brake cylinder, said passage having a rel striction interposedtherein, a timing reservoir,

meansfor supplying uid to said reservoir at a restricted rate from a point in said passage on the side ofthe restriction remote from the brake cylinder, valve` means subject to .the opposing pressures of the fluid` in saidtiming `reservoir and of the fluid inea chamber constantly open to said passagewat a point in` said passage intermediate the restriction `andthebrake cylinder for controlling the supply of fluid through said passage,A

`and a byfpass passage extending around said Valve means through `Whichfluid may flow to the brake cylinder.

brake equipment in combination, a plurality of` brake cylinders, ap-

, plicationmeans for` supplying :fluid under pressure `to `a communication through Vwhich fluid under pressure may be supplied to said brake cylinders, and a valve device for controlling the supg,

ply of fluid ,from `said communication to one of said brake cylinders, said valve devicecomprising a body having a` passage therein through which fluid is supplied from said communication to said brake cylinder, saidpassage having a re striction interposed therein, `,a timing` reservoir, means for supplying iiuid to said reservoirf at a restricted rate from a point in said passage `on the f side-,ofthe restriction remote from thebrakecylinder, valve means subjectto the opposing pressures of the fluid in said timing reservoir and of the fluid in a chamber constantly open tosaid passage at a'point in said passage intermediate the restriction and the brake cylinder for controlling the supply of fluid through said passaga.

`and a by-pass passage extending `around said valve means through `which fluid `may iioW `to, the 'brake cylinder at a less Vrapid` ratethan through said restriction. i 1 i y 6. In a vehicle iiuid pressure brakeequipment,

in combination, braking means operative on the supply of fluid under pressure to effect an applic cation of the brakes, application `means for supplyingiiuid under pressureto a communication ,throught whichffluid under pressure may be supplied to said brakingmeans, said communication Ahaving a restriction interposed therein, a timing reservoir, meansforsupplying fluid at a restrictediraten-to said timing reservoir from said communication at a point thereinintermediate the restriction and the application means, abody 4having vav chamber therein always -opento said communicatiomat a .point therein, intermediate the restriction and the braking means, a `movable abutment subject to the opposing pressures of the fluid in said chamber and of the iiuidin `said timing reservoinyalVe `means operated by said abutment for controlling the supply of fluid `to said braking means through said communication, and biasing means yieldinglyfurging thevalve meansto a position to permit ilow of fluid through said communication.V c, c

, 7. In avehicle fluid. pressure brake equipment, in combination, braking means operative on an `increase in fluid pressure to eiect an application of the brakes, applicationmeans for supplying uidmunderpressure to and for releasing fluid `under pressure ironic a communicationuthrough V `which` fluid under pressure may be supplied to under pressure may be supplied to said brake and released from saidbraking-ineans, Asaid communication having a restrictionY interposed therein, a timing reservoir, means for supplying fluid to said timing reservoir at a restricted rate from said communication at 'a point therein intermediate the application means and said restriction, valve means for controlling the supply of fluid to said braking meansthrough said communication, saidvalve means being subject to the opposing pressures of the fluid in said timing reservoir and of the fluid in a chamber open to said communication at a point therein intermediate the restriction and the braking means, and a check valve operative to prevent flow of fluid from said communication to the timing reservoir and to permit flow of fluid from the timing reservoir to said communication.

Y 8. In a vehicle fluid pressure brake equipment, in combination, braking meansy operative on an increase in fluid pressure to effect an application of the brakes, application means for supplying fluid under pressure to and for releasing fluid under pressure from a communication through which uid under pressure may be supplied to and released from said braking means, said communication having a restriction interposed therein, a timing reservoir, means for supplying fluid to said timing reservoir at a restricted rate from said communication at a point therein intermediate the application means and said restriction, valve means for controlling the supply of fluid to said braking means through said communication, said valve means being subject -to the opposing pressures of the fluid in saidY timing `reservoir and of the fluid in a chamber open to'said communicationat a point therein intermediate the restriction and the braking means, and a check valve operative to prevent flow of fluid from said communication to the timing reservoir and to permit flow of fluid from the timing reservoir to said communication at a point in said communication intermediate the application means and said restriction.

9. In a vehicle fluid pressure brake equipment, in combination, braking means operative on an increase influid pressure to effect an application of the brakes, application means for supplying fluid under pressure to and for releasing fluid under pressure from a communication through which fluid under pressure may'be supplied to and released from said braking means, said cornmunication having a restriction interposed therein, a timing reservoir, valve means subject to the opposing pressures of the fluid in said timing reservoir and of the fluidin a chamber open to said communication at a point therein intermediate the restriction and the braking means for controlling the flow of fluid through said communication, means for supplying fluid to said timing reservoir at a restricted rate from said communication at a point therein intermediate the restriction and the application means, a passage connecting the timing-reservoir with said communication at a point therein intermediate the restriction and the application means, and a check valve operative to permit fluid to "flow from the timing reservoir to said communication and to prevent flow of fluid from said communicationto the timing reservoir through plication of the brakes, application means for` Supplying fluid under pressure to and for retion through which fluidunder pressure may be supplied to and released from said braking means, said communication having a restriction interposed therein, a timing reservoir, means for supplying fluid to said timing reservoir at a restricted rate from said communication at a point therein intermediate the application means and the restriction, valve means subject to the opposing pressures of the fluid inthe timing reservoir and of the fluid in a chamber open to said communication at a Vpoint therein intermediate the restriction and the braking means for controlling the flow of fluid through said communication, a by-pass passage extending around said restriction, and a check valve operative to prevent flow of fluid from the application means to the braking means through said passage and to permit flow of fluid from the braking means to the application means through said passage.

11. In a vehicle fluidpressure brake equipment, in combination, braking means operative on an increase in fluid pressure to effect an application of the brakes, application means forl Vposing pressures of the fluid in the timing reservoir and of the fluid in a chamber open to said communication at a point therein intermediate the restriction and the braking means for controlling the flow of fluid through said communication, a by-pass passage extending around said valve means, and a check valve operative to prevent flow of fluid from the application means to the braking means through said passage and to permit flow of uid from the braking means to' the application means through said passage. i

12. In a vehicle fluid pressure brake equipment, in combination, braking means operated on an increase in the pressure of the fluid supplied thereto to effect an application of the brakes, application means for supplying fluid,

Voir, means for supplying fluid to said timing reservoir at a restricted rate from said com- Amunication at a'point therein intermediate the application means and the restriction, valve means subject to the opposing pressures oi the fluid in the timing reservoir and of the fluid in an operating chamber for controlling the flow of fluid through said communication, and means for supplying fluid to said operating chamber from said communication at a point therein intermediate the valve means and the braking means and on the side of the restriction adjacent the braking means.

`13. In a vehicle fluid pressure brake equipment, in combination, braking means operated cn an increase in the pressure of the fluid supplied thereto to effect an application of the brakes, application means for supplying fluid under pressure to a communication through which fluid under pressure may be supplied to said braking means, said leasingy fluid under pressure from a communicacommunication having a restriction interposed application means, and valve means subject to the opposing pressures of the fluid in said volume chamber and of the fluid in an operating chamber for controlling the flow of fluid through said communication, said operating chamber being always open to said communication at a point therein intermediate the restriction and the brake cylinder.

20. In a vehicle fluid pressure brake equipment, in combination, a source of fluid under pressure, a brake cylinder, application means for supplying fluid under pressure from said source to a communication through which fluid under pressure may be supplied to the brake cylinder through a restriction, a volume chamber, means for supplying fluid under pressure to said volume chamber at a restricted rate from a point in said communication intermediate said restriction and the application means, and valve means subject to the opposing pressures of the fluid in said volume chamber and of the fluid in an operating chamber for controlling the ilow of fluid through said communication at a point therein intermediate the restriction and the brake cylinder, said operating chamber being always Open to said communication at a point therein intermediate vthe valve means and the brake cylinder.

21. In a Vehicle fluid pressure brake equipment,

in combination, a source `of fluid under pressure,

a brake cylinder, application means for supplying fluid under pressure from said source to a communication through which uid under pressure may be supplied to the brake cylinder through a restriction, a pressure chamber, means for supplying fluid under pressure to said pressure chamber from a point in said communication intermediate said restriction and the application means, an operating chamber, and valve means subject to the opposing pressures of the fluid in the pressure chamber and of the fluid in said operating chamber for controlling the flow of fluid through said communication, said valve means being operative to restrict the flow of fluid through said communication upon a predetermined increase in the pressure of the fluid in the pressure chamber above the pressure of the fluid in the operating chamber, said operating chamber being constantly open to said communication at a point therein intermediate the restriction and the brake cylinder.

22. In a vehicle iluid pressure brake equipment, in combination, a source of fluid under pressure, a brake cylinder, application means for supplying fluid under pressure from said source to a communication through which fluid under pressure may be supplied to the brake cylinder through a restriction, a pressure chamber, means for supplying iluid under pressure to said pressure chamber from a point in said communication intermediate said restriction and the application means, an operating chamber, and valve meansV subject to the opposing pressures of the fluid in the pressure chamber and of the fluid in said operating chamber for controlling the flow of fluid through said communication at a point therein intermediatethe restriction and the brake cylinder, said valve means being operative upon a predeterminedv increase in the pressure of the fluid in the pressure chamber above the pressure of the fluid in the` operating chamber to restrict the ilow of fluid through said communication, said operating chamber being always open to said communicationat a point therein intermediate the valve means and the brake cylinder.

23. In a vehicle fluid pressure brake equipment, in combination, a brake cylinder, a source of fluid under pressure, application means for supplying fluid under pressure from said source to a communication through which fluid may be supplied to said brake cylinder, said application means being also operative to release fluid from said communication, valve means subject to the opposing pressures of the fluid in a pressure chamber and of the fluid in an operating chamber for controlling the rate of flow of fluid through said communication, said valve means being operative on an increase in the pressure of the fluid in the pressure chamber to a predetermined value above that in the operating chamber to restrict the rate of flow of fluid through said communication, means for supplying fluid at a restricted f rate to said pressure chamber from said communication, means for supplying iluid to said operating chamber from said communication at a point therein intermediate the brake cylinder and the point in said communication from which lluid. is supplied to the pressure chamber, means associated with said communication and operative on the'flow of fluid through said communication to the brake cylinder to cause a reduction in the pressure of the fluid in the portion` of the communication from which fluid is supplied to the operating chamber below the pressure of the fluid in the portion of the communication from which fluid is supplied to the pressure chamber, a passage through which fluid may ilow from the pressure chamber to` said communication at a rapid rate, and a check valve for preventing flow of fluid from said communication to the pressure chamber through said passage.

CLYDE C. FARMER. 

